Bucky & Jack
Okay, chalk that up to learning. Even two hundred years of reading people didn't make you an expert on everyone--it was almost nice to be reminded of that sometimes, that he wasn't perfect at this.
He would've told Bucky not to apologise or feel bad, but that would've required pulling back. And he wasn't going to do that until the other man did. It was fighting most of his instincts not to put his hands back--he knew he had a style when he kissed people, and didn't see the point in changing what had pretty much worked--but Jack kept his hands down, while he gently felt against the other man's lips and tongue with his own, not being near as forceful as he might have been with other people.